Study of Soluble CD52 as a Tumor Marker and Indicator of Disease Activity in Chronic Lymphocytic Leukemia

Background: Chronic Lymphocytic Leukemia (CLL) is non-curable disease and has variable course among patients. In some patients it progresses fast despite sever treatment and is fatal within 2 to 3 years whereas others require no or minimal treatment and die due to cause other than CLL. The aim of this work was to investigate the circulating soluble CD52 in blood of CLL patients to explore its usefulness as diagnostic and prognostic biomarker. Methods: This study included 40 cases who were divided into four equal groups; group 1 was patients who were newly diagnosed with CLL, group 2 was cases of chronic lymphocytic leukaemia with complete remission after treatment, group 3 was cases of relapsed chronic lymphocytic leukaemia and group 4 was the control group. All patients were subjected to clinical examinations ,laboratory investigations including: (complete blood counting, liver function tests, kidney function test, LDH Immunophenotyping) and specific laboratory investigation of soluble CD52 using ELISA. Results: ROC curve for SCD52 to discriminate between newly diagnosed cases and control group with cut of point 201(ng / ml) and AUC 0.890 with p value 0.003 with sensitivity and specificity 80% and to discriminate between relapsed cases from complete remission cases with cutoff point 345 (ng / ml) and AUC 0.840 with (p value 0.010) with sensitivity 80% and specificity 90%. In group 1and group 3, there were positive correlation between SCD52 and staging system,  absolute lymphocytic count and LDH, significant negative correlation between SCD52 and platelet count. Conclusions: The role ofsCD52 as diagnostic and prognostic marker for CLL due to its relation to CLL disease activity.